e.g. https://ci.chromium.org/buildbot/chromium.clang/CrWinAsan/1145

[ RUN      ] AddressSanitizerTests.TestAddressSanitizer
../../sandbox/win/src/address_sanitizer_test.cc(104): error: Value of: strstr(data.c_str(), &source_file_basename[last_slash])
  Actual: false
Expected: true
The stack trace doesn't have a correct filename:
=================================================================
==1476==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x11f8397001d8 at pc 0x7ff6781e122a bp 0x00a69150f380 sp 0x00a69150f388
WRITE of size 4 at 0x11f8397001d8 thread T0
    #0 0x7ff6781e1229 in AddressSanitizerTests_Report+0x229 (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0x1229)
    #1 0x7ff6782a1b6f in sandbox::DispatchCall+0x851 (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0xc1b6f)
    #2 0x7ff6782a45b0 in wmain+0x285 (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0xc45b0)
    #3 0x7ff6786ea2bf in __scrt_common_main_seh f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283
    #4 0x7fff65fd2773 in BaseThreadInitThunk+0x13 (C:\Windows\System32\KERNEL32.DLL+0x12773)
    #5 0x7fff660f0d50 in RtlUserThreadStart+0x20 (C:\Windows\SYSTEM32\ntdll.dll+0x70d50)
0x11f8397001d8 is located 0 bytes to the right of 168-byte region [0x11f839700130,0x11f8397001d8)
allocated by thread T0 here:
    #0 0x7ff6786ce691 in malloc c:\b\c\b\crwinasan\src\third_party\llvm\projects\compiler-rt\lib\asan\asan_malloc_win.cc:60
    #1 0x7ff6786e73c2 in operator new f:\dd\vctools\crt\vcstartup\src\heap\new_scalar.cpp:35
    #2 0x7ff6781e10f1 in AddressSanitizerTests_Report+0xf1 (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0x10f1)
    #3 0x7ff6782a1b6f in sandbox::DispatchCall+0x851 (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0xc1b6f)
    #4 0x7ff6782a45b0 in wmain+0x285 (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0xc45b0)
    #5 0x7ff6786ea2bf in __scrt_common_main_seh f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283
    #6 0x7fff65fd2773 in BaseThreadInitThunk+0x13 (C:\Windows\System32\KERNEL32.DLL+0x12773)
    #7 0x7fff660f0d50 in RtlUserThreadStart+0x20 (C:\Windows\SYSTEM32\ntdll.dll+0x70d50)
SUMMARY: AddressSanitizer: heap-buffer-overflow (C:\b\s\w\ir\out\Release\sbox_integration_tests.exe+0x1229) in AddressSanitizerTests_Report+0x229
Shadow bytes around the buggy address:
  0x0419409dffe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0419409dfff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0419409e0000: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  0x0419409e0010: 00 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa
  0x0419409e0020: fa fa fa fa fa fa 00 00 00 00 00 00 00 00 00 00
=>0x0419409e0030: 00 00 00 00 00 00 00 00 00 00 00[fa]fa fa fa fa
  0x0419409e0040: fa fa fa fa fd fd fd fd fd fd fd fd fd fd fd fd
  0x0419409e0050: fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa
  0x0419409e0060: fa fa fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0419409e0070: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  0x0419409e0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==1476==ABORTING
Stack trace:
Backtrace:
	testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop [0x00007FF6782DBC02+214]
	testing::internal::AssertHelper::operator= [0x00007FF6782DAB83+265]
	sandbox::AddressSanitizerTests_TestAddressSanitizer_Test::TestBody [0x00007FF6781E2A89+6199]
[  FAILED  ] AddressSanitizerTests.TestAddressSanitizer (700 ms)



First happened in https://ci.chromium.org/buildbot/chromium.clang/CrWinAsan/1092 It contains https://chromium-review.googlesource.com/1164532 which tweaked the symbol_level, which is probably the cause for this.

Do the win/asan bots need to use symbol_level=2?